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Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change1. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification2-4. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius5. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO2) per year with extraction costs of approximately US$80-180 per tonne of CO2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.
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Agricultura , Dióxido de Carbono/aislamiento & purificación , Productos Agrícolas , Sedimentos Geológicos/química , Calentamiento Global/prevención & control , Objetivos , Silicatos/química , Atmósfera/química , Brasil , China , Política Ambiental/economía , Política Ambiental/legislación & jurisprudencia , Calentamiento Global/economía , India , Hierro/aislamiento & purificación , Minería , Política , Probabilidad , Silicatos/aislamiento & purificación , Acero/aislamiento & purificación , Temperatura , Factores de Tiempo , Estados UnidosRESUMEN
The contributions of anti-Topoisomerase 1 (Top1) autoantibodies to the pathophysiology of diffuse cutaneous systemic sclerosis (dcSSc), the most aggressive scleroderma subtype, are unknown. Top1 catalyzes DNA relaxation and unwinding in cell nuclei, a site previously considered inaccessible to antibodies. The discovery of autoantibodies in systemic lupus erythematosus that penetrate nuclei and inhibit DNA repair raised the possibility that nuclear-penetrating autoantibodies contribute to mechanisms of autoimmunity. Here we show that an anti-Top1 autoantibody produced by a single B cell clone from a patient with dcSSc penetrates live cells and localizes into nuclei. Functionally, the autoantibody inhibits formation of the Top1 cleavage complex necessary for DNA nicking, which distinguishes it from cytotoxic camptothecin Top1 inhibitors used in cancer therapy that trap the cleavage complex rather than preventing its formation. Discovery of a patient-derived cell-penetrating scleroderma anti-Top1 autoantibody that inhibits Top1 cleavage complex formation supports the hypothesis that anti-Top1 autoantibodies contribute to cellular dysfunction in dcSSc and offers a valuable antibody reagent resource for future studies on anti-Top1 autoantibody contributions to scleroderma pathophysiology.
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Autoanticuerpos , Núcleo Celular , ADN-Topoisomerasas de Tipo I , ADN-Topoisomerasas de Tipo I/inmunología , ADN-Topoisomerasas de Tipo I/metabolismo , Humanos , Autoanticuerpos/inmunología , Núcleo Celular/metabolismo , Esclerodermia Difusa/inmunología , Esclerodermia Difusa/tratamiento farmacológicoRESUMEN
BACKGROUND: With the widespread adoption of Blood Establishment Computer Systems and other Blood Collection and Transfusion Service (BCTS) clinical information systems (CIS), electronic blood donor, product, and patient data are now routinely required for clinical, regulatory, operational, and quality needs. That data are often not readily accessible for such secondary use within CIS databases, particularly for applications with significant data availability requirements such as machine learning and artificial intelligence. Data replication provides one avenue by which CIS data can be made more readily available. STUDY DESIGN AND METHODS: Members of the AABB's Information Systems Committee along with institutional information technology colleagues provided a multi-institutional viewpoint on data replication through the lens of BCTS specific use cases. Case studies of informatics offerings leveraging such technologies were also elicited. RESULTS: Six distinct use cases describe the potential role of data replication including the creation of data warehouses for frontline laboratory staff. Specific BCTS examples for each use case are presented to highlight the value of data replication, including visualization of critical inventory (O red blood cells, HLA-compatible platelets) and utilization analytics for patient blood management. Two case studies describe the approach to implement such technologies to (1) optimize staffing via laboratory workload reporting and (2) improve access to blood via antigen-negative blood product location services. DISCUSSION: Data replication and warehousing can empower BCTS analytic offerings not otherwise natively available through one's CIS to improve patient care and laboratory operations.
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Transfusión Sanguínea , Humanos , Transfusión Sanguínea/métodos , Data Warehousing , Bancos de SangreRESUMEN
PURPOSE: The Akesis Galaxy RTi (AK) is a novel rotational 60 Co-based cranial stereotactic radiosurgery (SRS) system. While similar systems have been compared against the fixed-source Leksell Gamma Knife (GK) system using stylized phantoms, dosimetric plan quality with realistic anatomy has yet to be characterized for this or any other rotating system versus GK. This study aims to benchmark AK dosimetric performance against GK by retrospectively replanning previously-treated GK patients at our institution. METHODS: Thirteen patients, previously treated on a GK Icon, were re-planned on the AK treatment planning system using the same prescription doses and isodoses as the original GK plans. The cohort includes patients treated for brain metastases, schwannomas, pituitary adenomas, trigeminal neuralgias, and arteriovenous malformations. Plans are evaluated with target coverage metrics (Dmin , Dmean , D95% , V150% ) and dose conformality indices: Radiation Therapy Oncology Group conformity index (CI), selectivity, Paddick CI (PCI), gradient index (GI). RESULTS: AK plans use fewer shots and larger collimation compared to GK plans, resulting in statistically significant reductions in treatment time (p = 0.047) by as much as 88.4 minutes while maintaining comparable target V100% . For most metastatic cases, GK produces higher Dmin (16.0-25.9 vs. 12.5-24.3 Gy, p = 0.008) while AK produces higher V150% (0.03-14.92 vs. 0.02-11.59 cc, p = 0.028). For non-metastatic cases, GK provides superior CI (p = 0.025) and GI (p = 0.044). No statistically significant differences were found in the remaining metrics. CONCLUSION: This cohort demonstrates that the AK system is able to achieve largely comparable dosimetric results to GK, typically with shorter treatment times. Further investigation with a larger cohort is underway.
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Neoplasias Encefálicas , Neoplasias Hipofisarias , Radiocirugia , Humanos , Radiocirugia/métodos , Estudios Retrospectivos , Neoplasias Encefálicas/secundario , Radiometría , Neoplasias Hipofisarias/radioterapia , Neoplasias Hipofisarias/cirugía , Planificación de la Radioterapia Asistida por Computador/métodos , Dosificación RadioterapéuticaRESUMEN
The continual rise in sulfadoxine (SDX) resistance affects the therapeutic efficacy of sulfadoxine-pyrimethamine; therefore, careful monitoring will help guide its prolonged usage. Mutations in Plasmodium falciparum dihydropteroate synthase (Pfdhps) are being surveilled, based on their link with SDX resistance. However, there is a lack of continuous analyses and data on the potential effect of molecular markers on the Pfdhps structure and function. This study explored single-nucleotide polymorphisms (SNPs) in Pfdhps that were isolated in Africa and other countries, highlighting the regional distribution and its link with structure. In total, 6336 genomic sequences from 13 countries were subjected to SNPs, haplotypes, and structure-based analyses. The SNP analysis revealed that the key SDX resistance marker, A437G, was nearing fixation in all countries, peaking in Malawi. The mutation A613S was rare except in isolates from the Democratic Republic of Congo and Malawi. Molecular docking revealed a general loss of interactions when comparing mutant proteins to the wild-type protein. During MD simulations, SDX was released from the active site in mutants A581G and A613S before the end of run-time, whereas an unstable binding of SDX to mutant A613S and haplotype A437A/A581G/A613S was observed. Conformational changes in mutant A581G and the haplotypes A581G/A613S, A437G/A581G, and A437G/A581G/A613S were seen. The radius of gyration revealed an unfolding behavior for the A613S, K540E/A581G, and A437G/A581G systems. Overall, tracking such mutations by the continuous analysis of Pfdhps SNPs is encouraged. SNPs on the Pfdhps structure may cause protein-drug function loss, which could affect the applicability of SDX in preventing malaria in pregnant women and children.
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Antimaláricos , Dihidropteroato Sintasa , Malaria Falciparum , Plasmodium falciparum , Niño , Femenino , Humanos , Embarazo , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Dihidropteroato Sintasa/genética , Combinación de Medicamentos , Resistencia a Medicamentos/genética , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/genética , Simulación del Acoplamiento Molecular , Mutación , Sulfadoxina/farmacología , Sulfadoxina/uso terapéutico , Tetrahidrofolato Deshidrogenasa/genéticaRESUMEN
A key drawback to monitoring the emergence and spread of antimalarial drug resistance in sub-Saharan Africa is early detection and containment. Next-generation sequencing methods offer the resolution, sensitivity, and scale required to fill this gap by surveilling for molecular markers of drug resistance. We performed targeted sequencing using molecular inversion probes to interrogate five Plasmodium falciparum genes (pfcrt, pfmdr1, pfdhps, pfdhfr, and pfk13) implicated in chloroquine, sulfadoxine-pyrimethamine (SP), and artemisinin resistance in two sites in Ghana. A total of 803 dried blood spots from children aged between 6 months and 14 years presenting with uncomplicated P. falciparum malaria at the Begoro District Hospital in Begoro and the Ewim Polyclinic in Cape Coast, Ghana, from 2014 to 2017 were prepared on filter paper. Thirteen years after the removal of drug pressure, chloroquine-sensitive parasite strains with pfcrt K76 have increased nearly to fixation in Begoro, in the forest area (prevalence = 95%), but at a lower rate in Cape Coast, in the coastal region (prevalence = 71%, Z = -3.5, P < 0.001). In addition, pfmdr1 184F-bearing parasites are under strong selection. The pfdhfr/pfdhps quadruple genotype ( IRNG K), associated with SP resistance, is near saturation. Our study identified at a 2 to 10% prevalence pfdhps 581G, which is a sulfadoxine resistance marker that correlates with the failure of SP prophylaxis in pregnancy and which has not been observed in Ghana. The differences in the reexpansion of chloroquine-sensitive strains observed at the two study sites, the stronger SP resistance, and the high prevalence of pfmdr1 184F should be further monitored to inform malaria control strategies in Ghana.
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Antimaláricos/uso terapéutico , Resistencia a Medicamentos/genética , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Adolescente , Artemisininas/uso terapéutico , Niño , Preescolar , Cloroquina/uso terapéutico , Combinación de Medicamentos , Ghana , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactante , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum/aislamiento & purificación , Pirimetamina/uso terapéutico , Sulfadoxina/uso terapéuticoRESUMEN
A key challenge in the development of novel chemotherapeutics is the design of molecules capable of selective toxicity to cancer cells. Antibodies have greater target specificity compared to small molecule drugs, but most are unable to penetrate cells, and predominantly target extracellular antigens. A nuclear-penetrating anti-DNA autoantibody isolated from the MRL/lpr lupus mouse model, 3E10, preferentially localizes to tumors, inhibits DNA repair, and selectively kills cancer cells with defects in DNA repair. A murine divalent single chain variable fragment of 3E10 with mutations for improved DNA binding affinity, 3E10 (D31N) di-scFv, has previously been produced in P. pastoris and yielded promising pre-clinical findings, but is unsuitable for clinical testing. The present study reports the design, expression and testing of a panel of humanized 3E10 (D31N) di-scFvs, some of which contain CDR substitution. These variants were expressed in a modified CHO system and evaluated for their physicochemical attributes and ability to penetrate nuclei to selectively cause DNA damage accumulation in and kill cancer cells with DNA repair defects. Secondary structure was conserved and most variants retained the key characteristics of the murine 3E10 (D31N) di-scFv produced in P. pastoris. Moreover, several variants with CDR substitutions outperformed the murine prototype. In conclusion, we have designed several humanized variants of 3E10 (D31N) di-scFv that have potential for application as monotherapy or conjugates for targeted nuclear drug delivery.
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Anticuerpos Antinucleares/genética , Anticuerpos Antinucleares/inmunología , Autoanticuerpos/genética , Autoanticuerpos/inmunología , ADN/genética , ADN/inmunología , Ingeniería de Proteínas/métodos , Animales , Anticuerpos Antinucleares/uso terapéutico , Autoanticuerpos/uso terapéutico , Daño del ADN/inmunología , RatonesRESUMEN
OBJECTIVES: To evaluate radiation reduction by reducing fluoroscopy pulse rate in diagnostic cardiac catheterizations and percutaneous coronary interventions (PCI) as well as outcomes at 30 days and six months. BACKGROUND: Radiation exposure to the public at large has increased dramatically over the past three decades, and the cardiac catheterization laboratory is a large contributor. Fluoroscopy pulse rate is one way to decrease radiation exposure. METHODS: Fluoroscopy pulse rate was reduced from 10 pulses/sec (p/s) to 7.5 p/s as part of an internal quality improvement project. A retrospective analysis of all cardiac catheterizations was performed, evaluating Air KERMA at the interventional reference point (Ka, r ), Air KERMA area product (PKA ), procedural complications and major adverse cardiac events at 30 days and 6 months. RESULTS: In diagnostic catheterization median PKA (µGy·m2 ) and Ka,r (mGy) were significantly reduced (PKA - 5,613.3 vs. 4,400, P < 0.001; Ka,r - 703.0 vs. 621.0, P = 0.041). In PCI, median PKA and Ka,r were further reduced (PKA - 13,481.6 vs. 10,648.0, P < 0.001; Ka,r - 1787.0 vs. 1,459.0, P = 0.002). There was no difference in complications, fluoroscopy time or number of stents placed. There was no difference in MACE after adjustment for number of STEMIs. CONCLUSIONS: Reducing fluoroscopy pulse rates to 7.5 from 10 is an effective way to reduce patient radiation exposure across meaningful dose indices. A pulse rate of 7.5 p/s is safe, with no difference in complications or outcomes. A fluoroscopy pulse rate of 7.5 p/s should be given strong consideration for a new standard. © 2016 Wiley Periodicals, Inc.
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Cateterismo Cardíaco/métodos , Fluoroscopía/métodos , Traumatismos por Radiación/prevención & control , Medición de Riesgo/métodos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/cirugía , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Intervención Coronaria Percutánea , Dosis de Radiación , Traumatismos por Radiación/epidemiología , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Access to a reliable source of electricity creates significant benefits for developing communities. Smaller versions of electricity grids, known as microgrids, have been developed as a solution to energy access problems. Using attributional life cycle assessment, this project evaluates the environmental and energy impacts of three photovoltiac (PV) microgrids compared to other energy options for a model village in Kenya. When normalized per kilowatt hour of electricity consumed, PV microgrids, particularly PV-battery systems, have lower impacts than other energy access solutions in climate change, particulate matter, photochemical oxidants, and terrestrial acidification. When compared to small-scale diesel generators, PV-battery systems save 94-99% in the above categories. When compared to the marginal electricity grid in Kenya, PV-battery systems save 80-88%. Contribution analysis suggests that electricity and primary metal use during component, particularly battery, manufacturing are the largest contributors to overall PV-battery microgrid impacts. Accordingly, additional savings could be seen from changing battery manufacturing location and ensuring end of life recycling. Overall, this project highlights the potential for PV microgrids to be feasible, adaptable, long-term energy access solutions, with health and environmental advantages compared to traditional electrification options.
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Cambio Climático , Suministros de Energía Eléctrica , Electricidad , Ambiente , Humanos , ReciclajeRESUMEN
Aortic stenosis in combination with end-stage renal disease (ESRD) is a high-risk combination for surgical valve replacement and little data exists on the role of transcatheter aortic valve replacement (TAVR) Pooled retrospective data from eight experienced TAVR sites suggests that TAVR can be accomplished in ESRD patients with first generation percutaneous valve at a risk similar to surgical approaches. Even with TAVR, valve replacement in the ESRD patient remain high risk and future improvements in technology and approaches to this poorly studied group are needed.
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Implantación de Prótesis de Válvulas Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Estenosis de la Válvula Aórtica/cirugía , Humanos , Fallo Renal Crónico/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
5-Fr transradial sheathless guide technique using a 4-Fr mother-child technique can be accomplished with excellent clinical success An enhanced risk for local traumatic injury to the radial artery was observed that may stem from the imperfect transition and taper between catheters, or friction inherent in the catheter surface design, that technologic advances may be able to address in the future If larger sheath technology is not feasible, this sheathless approach presents an option whether the risk/benefits appear favorable despite the potential from radial artery trauma.
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Catéteres Cardíacos , Enfermedad de la Arteria Coronaria/cirugía , Intervención Coronaria Percutánea/instrumentación , Arteria Radial , Grado de Desobstrucción Vascular , Femenino , Humanos , MasculinoRESUMEN
"Climate dice," describing the chance of unusually warm or cool seasons, have become more and more "loaded" in the past 30 y, coincident with rapid global warming. The distribution of seasonal mean temperature anomalies has shifted toward higher temperatures and the range of anomalies has increased. An important change is the emergence of a category of summertime extremely hot outliers, more than three standard deviations (3σ) warmer than the climatology of the 1951-1980 base period. This hot extreme, which covered much less than 1% of Earth's surface during the base period, now typically covers about 10% of the land area. It follows that we can state, with a high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming because their likelihood in the absence of global warming was exceedingly small. We discuss practical implications of this substantial, growing, climate change.
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Cambio Climático/historia , Cambio Climático/estadística & datos numéricos , Estaciones del Año , Temperatura , Historia del Siglo XX , Historia del Siglo XXI , Opinión PúblicaRESUMEN
In the aftermath of the March 2011 accident at Japan's Fukushima Daiichi nuclear power plant, the future contribution of nuclear power to the global energy supply has become somewhat uncertain. Because nuclear power is an abundant, low-carbon source of base-load power, it could make a large contribution to mitigation of global climate change and air pollution. Using historical production data, we calculate that global nuclear power has prevented an average of 1.84 million air pollution-related deaths and 64 gigatonnes of CO2-equivalent (GtCO2-eq) greenhouse gas (GHG) emissions that would have resulted from fossil fuel burning. On the basis of global projection data that take into account the effects of the Fukushima accident, we find that nuclear power could additionally prevent an average of 420,000-7.04 million deaths and 80-240 GtCO2-eq emissions due to fossil fuels by midcentury, depending on which fuel it replaces. By contrast, we assess that large-scale expansion of unconstrained natural gas use would not mitigate the climate problem and would cause far more deaths than expansion of nuclear power.
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Gases , Efecto Invernadero , Mortalidad , Plantas de Energía NuclearRESUMEN
Heat shock proteins (HSPs), especially Hsp70 (HSPA1), have been associated with cellular protection from various cellular stresses including heat, hypoxia-ischemia, neurodegeneration, toxins, and trauma. Endogenous HSPs are often synthesized in direct response to these stresses but in many situations are inadequate in protecting cells. The present study addresses the transduction of Hsp70 into cells providing protection from acute oxidative stress by H2O2. The recombinant Fv-Hsp70 protein and two mutant Fv-Hsp70 proteins minus the ATPase domain and minus the ATPase and terminal lid domains were tested at 0.5 and 1.0 µM concentrations after two different concentrations of H2O2 treatment. All three recombinant proteins protected SH-SY5Y cells from acute H2O2 toxicity. This data indicated that the protein binding domain was responsible for cellular protection. In addition, experiments pretreating cells with inhibitors of antioxidant proteins catalase and gamma-glutamylcysteine synthase (GGCS) before H2O2 resulted in cell death despite treatment with Fv-Hsp70, implying that both enzymes were protected from acute oxidative stress after treatment with Fv-Hsp70. This study demonstrates that Fv-Hsp70 is protective in our experiments primarily by the protein-binding domain. The Hsp70 terminal lid domain was also not necessary for protection.
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Peróxido de Hidrógeno , Neuroblastoma , Humanos , Peróxido de Hidrógeno/toxicidad , Cisteína Sintasa , Catalasa , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas Recombinantes , Adenosina TrifosfatasasRESUMEN
Mites of the genus Thyreophagus (Acari: Acaridae) are distributed worldwide; they inhabit concealed habitats and include several beneficial and economically important species. However, species identification is difficult because many species are poorly described or delimited and their phoretic stages are unknown or uncorrelated. Furthermore, Thyreophagus is interesting because it includes entirely asexual (parthenogenetic) species. However, among the 34 described species of Thyreophagus, the asexual status is confirmed through laboratory rearing for only two species. Here, we provide detailed descriptions of five new species from North America (four) and Europe (one) based on adults and phoretic heteromorphic deutonymphs. Four of these species were asexual, while one was sexual. For most of these mites, the asexual status was confirmed and phoretic deutonymphs were obtained through rearing in the lab. We show that asexual mites retain seemingly functional copulatory and sperm storage systems, indicating that these lineages have relatively short evolutionary lifespans. One North American species, Thyreophagus ojibwe, was found in association with the native American chestnut Castanea dentata, suggesting a possibility that this mite can be used to control chestnut blight in North America. We also provide a diagnostic key to females, males, and heteromorphic deutonymphs of the Thyreophagus species in the world.
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The relationship of oxygen uptake [Formula: see text] to ventilation [Formula: see text], i.e., oxygen uptake efficiency (OUE) is known to differ between normal subjects and patients with congestive heart failure. However, only the oxygen uptake efficiency slope (OUES, i.e., slope of [Formula: see text] has previously been reported. To understand the physiology and to improve the usefulness of OUE in assessing cardiovascular function, we analyzed the complete response pattern of OUE during entire incremental exercise tests and ascertained effect of age, body size, gender, fitness, and ergometer type on exercise OUE to generate reference values in normal healthy subjects. We investigated the effect of age, gender, and fitness on OUE using incremental cardiopulmonary exercise in 474 healthy subjects, age 17-78 years, of which 57 were highly fit. The final methods of OUE analysis were: (1) OUE plateau at the highest values (OUEP), (2) OUE at anaerobic threshold (OUE@AT), and (3) OUES using the entire exercise period. The OUEP and OUE@AT were similar, highly reproducible, less variable than the OUES (p < 0.0001), and unaffected by the study sites or types of ergometry. The resultant prediction equations from 417 normal subjects for men were OUEP (mL/L) = 42.18 - 0.189 × years + 0.036 × cm and OUES [L/min/log(L/min)] = -0.610 - 0.032 × years + 0.023 × cm + 0.008 × kg. For women, OUEP (mL/L) = 39.16 - 0.189 × years + 0.036 × cm and OUES [L/min/log(L/min)] = -1.178 - 0.032 × years + 0.023 × cm + 0.008 × kg. OUE@AT was similar to OUEP. Extreme fitness has a minimal effect on OUEP. OUEP is advantageous, since it measures maximal oxygen extraction from ventilated air but does not require high intensity exercise. The OUEP is a non-invasive parameter dependent only on age, gender, height, and cardiovascular health.
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Consumo de Oxígeno/fisiología , Oxígeno/farmacocinética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Umbral Anaerobio/fisiología , Eficiencia/fisiología , Ejercicio Físico/fisiología , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/metabolismo , Aptitud Física/fisiología , Valores de Referencia , Adulto JovenRESUMEN
We find evidence that black soot aerosols deposited on Tibetan glaciers have been a significant contributing factor to observed rapid glacier retreat. Reduced black soot emissions, in addition to reduced greenhouse gases, may be required to avoid demise of Himalayan glaciers and retain the benefits of glaciers for seasonal fresh water supplies.
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OBJECTIVE: Early selection steps preventing autoreactive naive B cell production are often impaired in patients with autoimmune diseases, but central and peripheral B cell tolerance checkpoints have not been assessed in patients with systemic sclerosis (SSc). This study was undertaken to characterize early B cell tolerance checkpoints in patients with SSc. METHODS: Using an in vitro polymerase chain reaction-based approach that allows the expression of recombinant antibodies cloned from single B cells, we tested the reactivity of antibodies expressed by 212 CD19+CD21low CD10+IgMhigh CD27- new emigrant/transitional B cells and 190 CD19+CD21+CD10-IgM+CD27- mature naive B cells from 10 patients with SSc. RESULTS: Compared to serum from healthy donors, serum from patients with SSc displayed elevated proportions of polyreactive and antinuclear-reactive new emigrant/transitional B cells that recognize topoisomerase I, suggesting that defective central B cell tolerance contributes to the production of serum autoantibodies characteristic of the disease. Frequencies of autoreactive mature naive B cells were also significantly increased in SSc patients compared to healthy donors, thus indicating that a peripheral B cell tolerance checkpoint may be impaired in SSc. CONCLUSION: Defective counterselection of developing autoreactive naive B cells in SSc leads to the production of self antigen-specific B cells that may secrete autoantibodies and allow the formation of immune complexes, which promote fibrosis in SSc.
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Autoantígenos/inmunología , Linfocitos B/inmunología , Tolerancia Inmunológica , Esclerodermia Sistémica/inmunología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Nuclear-penetrating anti-DNA autoantibodies have therapeutic potential as delivery agents and in targeting DNA and the DNA damage response (DDR). Derivatives of such Abs have advanced to human testing in genetic disease and are in preparation for oncology clinical trials. DNA release associated with neutrophil extracellular traps (NETs) contributes to immunity, inflammation, and the pathophysiology of multiple diseases. The DDR contributes to mechanisms of NETosis, and we hypothesize that anti-DNA autoantibodies that localize into live cell nuclei and inhibit DNA repair will suppress release of NETs by activated neutrophils. In the current study we evaluated the impact of a nuclear-penetrating anti-DNA autoantibody that interferes with the DDR on decondensation and release of DNA and NETs by activated human granulocyte-like differentiated PLB-985 cells and neutrophils isolated from C57BL/6 mice. The response of cells pretreated with control or autoantibody to subsequent stimulators of NETosis, including PMA and the calcium ionophore ionomycin, was evaluated by DAPI and SYTOX Green stains, measurement of DNA release, analysis of histone citrullination by Western blot, or visualization of NETs by immunostaining and confocal fluorescence microscopy. Autoantibody treatment of the cells yielded significant inhibition of NADPH oxidase-dependent and independent NETosis. These findings establish the concept of nuclear-penetrating anti-DNA autoantibodies as modulators of neutrophil biology with potential for use in strategies to suppress NETosis.